Elastomeric railway car side bearing

ABSTRACT

A preloadable side bearing for railroad cars having a formed body portion of hard elastomeric material incorporated in a base which is adapted for attachment to a supporting surface, such as the truck bolster of a railroad car, with provision for an initial reduction in the overall height of the bearing in response to preloading forces and to then absorb substantial loading forces with resulting compressive depression of the body portion and wherein the body portion and base are formed of a material such as polyurethane. The mass is provided with an axial bore for the reception of a rod.

United States Patent Inventor John H. Van Moss,Jr.

Highland Park, Ill.

Appl. No. 43,835

Filed June 5, 1970 Patented Dec. 21, 197] Assignee Vanguard Corporation Chicago, Ill.

Continuation-impart of application Ser. No. 767,450, Oct. 14, 1968, now Patent No. 3,556,503, dated Jan. 19, 1971. This application June 5, 1970, Ser. No. 43,835

ELASTOMERIC RAILWAY CAR SIDE BEARING 5 Claims, 5 Drawing Figs.

Primary Examiner-Arthur L. La Point Assistant Examiner-Howard Beltran Altorney-Rummler and Snow ABSTRACT: A preloadable side bearing for railroad cars having a formed body portion of hard elastomeric material incorporated in a base which is adapted for attachment to a supporting surface, such as the truck bolster of a railroad car, with provision for an initial reduction in the overall height of the bearing in response to preloading forces and to then absorb substantial loading forces with resulting compressive depression of the body portion and wherein the body portion and base are formed of a material such as polyurethane. The mass is provided with an axial bore for the reception ofa rod.

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ELASTOMERIC RAILWAY CAR SIDE BEARING This invention is a continuation-in-part of my application Ser. No. 767,450, filed Oct. 14, 1968, issued Jan. 19, 1971 as US. Pat. No. 3,556,503 for SIDE BEARING FOR RAIL- ROAD CARS.

BACKGROUND OF THE INVENTION This invention relates to a preloadable side bearing for use with railroad cars and for positioning between the car body and a truck bolster to be compressed under preloading forces and receive forces encountered'as the car body swings to reduce harmonic rocking of the car body and resultingly reduce the frequency of derailments.

Side bearings have been known for many years embodying rollers movably mounted in a frame supported on a truck bolster which could be contacted by the car body. Also, preloaded side bearings are known utilizing spring-loaded cam systems resulting in a complicated construction. Insofar as solving the problem of harmonic rocking motion resulting in derailments, it has been known to utilize snubber members used in conjunction with the spring groups between the truck bolster and the side frame of the truck. None of the foregoing, as well as other variations thereof, have been found to provide an inexpensive structure which will reduce the harmonic condition which causes the car bodies to sway from side to side and create a problem which is known in the railroad industry as rock and roll." More specifically, this condition has been encountered with high covered hopper cars and some high side gondolas capable of carrying between 100 and 125 tons of material. These cars are normally approximately the same length as the standard rail and with the staggered joints between the rails, the harmonic condition was set up at some of the lower speeds of travel.

As now understood, this swinging of the car body from one side to the other contacted against the side bearing which is located between the car body and the truck bolster. The forces were transmitted through the bolster and into the spring group and the side frame of the truck. From there, the force went through the car journals and onto the axles on the outboard side of the wheels of the truck. This caused the wheels and the rail on that particular side to form a fulcrum point and the axles and wheels rotated about that fulcrum point, lifting the wheel from the track on the opposite side. This has not been a new condition. However, in the past, most of the time the wheels on the far side returned and made contact with the rail. In these newer cars with larger loads and greater frequen cy of the harmonic condition, the wheels were turning to the level and missing the rail, causing derailments. A second condition which is causing derailments is believed to be where the harmonic rocking of the car body becomes so violent that the loads transmitted down through the truck bolsters and frame into the wheels are great enough to actually turn the rail over.

At the present time, there are no firm specifications by the Association of American Railroads regarding resilient-type side bearings. However, it has been decided informally that such side bearings should have an initial preload of 5,000 pounds on each side of the car, with a deflection of the resilient side bearing of approximately one-fourth inch and as the car body rocks, the resistance of the side bearing should increase to 50,000 pounds with an additional deflection of approximately 1 inch. The side bearing disclosed herein substantially meets the foregoing informal specifications and contributes to a reduction of the problems which have resulted in derailments.

SUMMARY OF THE INVENTION An object of this invention is to provide a new and improved preloadable side bearing for use with railroad cars which reduces the likelihood of derailment in a railroad car.

Another object of the invention is to provide a preloadable side bearing for positioning between the frame of a railroad car and the truck bolster comprising a base member attachable to the truck bolster, a symmetrically shaped body portion of hard elastomeric material extending upwardly from the base with the periphery thereof being shaped to permit outward movement of the material without significantly increasing the overall dimension of the mass of material.

Still another object of the invention is to provide a preloadable side bearing wherein the base member and the body portion of elastomeric material are formed integrally of the same material.

An additional object of the invention is to provide a preloadable side bearing, as defined in the preceding paragraphs, and a combination thereof with a railroad car, wherein said elastomeric material has a hardness of approximately 50 Shore D Scale or harder and provides an initial deflection of the side bearing of approximately one-fourth inch under 5,000 pounds loading and limits additional deflection to approximately 1 inch under additional loading of approximately 50,000 pounds.

An additional object of the invention is to provide a preloading bearing, as defined in the preceding paragraphs, wherein the elastomeric side bearing is axially bored to receive a rod of a length less than the total length of the bore.

Further objects and advantages will become apparent from the following detailed description taken in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary, simplified elevational view of a portion of a railroad car body and truck bolster with the novel side bearing positioned therebetween.

FIG. 2 is a vertical section of the side bearing of the present invention.

FIG. 3 is a perspective view of a modified bearing of FIG. 4.

FIG. 4 is a vertical section of the device shown in FIG. 3.

FIG. 5 is a perspective view of the metal rod shown in full lines in FIG. 4.

DETAILED DESCRIPTION OF THE DRAWINGS Referring to FIG. 1, this figure illustrates the side bearing of the present invention as associated with a railroad car, wherein the truck bolster 10 underlies the car frame 12 of the car body. The preloaded side bearing of the present invention is generally indicated at 14 shown disposed between the bolster and car body frame. The bearing 14 is secured to the truck bolster 10 by bolts 16, while the upper surface thereof is in engagement with a plate 18 secured to the under side of the car frame 12.

A suitable elastomeric material for the side bearing has been found to be a polyurethane material and, in order for this material to handle the loads that can be expected in service, testing has shown that the material should have a hardness of approximately 50 Shore D Scale or harder. It has been found that these loads can approach 200,000 pounds just prior to derailment of a railroad car. One example of such material is Thiokols Solithane L-650.

The embodiment in FIG. 2 incorporates a base 20 containing apertures 22 in each flange 24, 26 and each containing a sleeve 28 for reception of a bolt 16 for anchoring to the bolster I0.

The main upstanding body member 30, integrally formed on base 20, is symmetrical and has a frustoconical shape with the wall extending at an angle of approximately upwardly from the upper surface of the base 20. The upper end 32 of the body member is contoured with the central part thereof being flat with an outer perimetrical part 34 sloping downwardly to the periphery 36.

The frustoconical shape provides maximum strength for the side bearing in the area where body member 30 joins the base 20 to prevent roll over of the side bearing in use.

This shaping of the upper surface of the side bearing permits a limited amount of the elastomeric material to compress under deflection forces.

The flat surface 32 may be impregnated with particles of either Teflon or molydisulfide to make the surface slippery to facilitate relative movement between this surface and the plate 18 depending from the car frame 12.

In order to reduce the amount of elastomeric material used in forming the side bearing of this embodiment, a low-cost rod 38 of metal or other material is positioned in a recess 40 in the base 20, the upper end of the rod 38 extending into the interior of the body member 30 axially. The rod 38 functions as a safety stop to limit tilting of the railroad car frame, as well as to limit the maximum deflection of the side bearing under maximum loading conditions of the railroad car, by causing the car frame, in effect, to bottom on the rod.

The device disclosed in FIGS. 3 and 4 comprises an upstanding body member 50 which is symmetrical and has a frustoconical like configuration with an integrally formed base 52, The base 52 is of identical size and shape as base 20 of the embodiment shown in FIG. 2. The base 52 is also provided with a pair of apertures 54 in the flanges 55, and eachcontaining a sleeve 56 for a bolt to fasten the bearing to the bolster l0.

The bearing is provided with a cylindrical opening or bore 58 extending axially from the uppermost surface of the bearing to the lower edge of base 52. The opening 58 is preferably 1% inches in diameter before shrinking during cooling after being removed from the mold. The overall height of the bearing is preferably inches but when installed, the height is compressed to 5 inches by the weight of the railroad car.

A cylindrical metal rod 60, having a diameter of preferably 1% inches and a length of approximately 4% inches, is frictionally seated in the opening 58, as shown in FIG. 4, whereby to restrict the maximum compression and deflection of the bearing, under maximum loading conditions, by causing the railroad car' frame, in effect, to bottom the rod 60. The rod 60 also functions as a safety stop to limit tilting of the railroad car frame. it is especially noted that the lower end of the opening is provided with a radius 62.

it is to be noted that the surface 62 extends outwardly and downwardly at an angle of approximately 22 from the area surrounding the top of the opening 58 whereby only the upper end 64 of the rod 60 and the immediate area around the opening 58 will bear against the car frame 18. Thus, with the preferable dimensions heretofore set forth, there will be an opening 64 approximating one-half inch in height below the lower end of rod 60 when the bearing is positioned on the bolster. Thus, this will allow the bearing to compress only approximately one-half inch under maximum loading conditions of 50,000 pounds or when the railroad car is standing on a curved angled track, and because of the additional rigidity of the bearing caused by the presence of the rod 60 positioned axially therein, the deflection of the bearing is minimal.

Also, because of the rod 60 and the radii 62 of the opening 58, the bearing will tend to compress in the area 64 under full load conditions and until the load end of rod 60 buttons on the truck bolster.

It is to be understood that numerous detail may be altered or omitted without departing from the spirit of this invention as defined by the following claims.

lclaim:

1. A side bearing for railroad cars comprising an upstanding symmetrical body member of frustoconical shape, the upper medial bearing surface being flat, a flanged base integrally formed on the lower end of said body member, said body member and base being formed solely of an elastomeric material having a hardness of at least 50 Shore D Scale, the perimeter of said upper surface extending downwardly and outwardly therefrom and merging with the sidewall of said body member, and a rod extending medially upwardly in said member from the lower surface of said base.

2. The device according to claim 1 wherein the body member and base are bored axially, a rod having a length less than the length of the bore positioned in said bore, and the rod bein frictionally seated in said bore.

3. he device according to claim 2 wherein the hardness of said elastomeric material is at least 50 to Shore D Scale.

4. A preloadable side bearing for positioning between the frame of a railroad car and the truck bolster comprising an integrally formed, flanged base and an upstanding symmetrical body member of frustoconical shape, said base and body member being formed of an elastomeric material having a hardness of at least 50 to 90 Shore D Scale, the medial portion of the upper surface of said body member being flat with perimetrical portions angled downwardly, a cylindrical rod embedded axially in said body member and having a length substantially less than the height of said base and body member, and an axial opening between the lower end of said rod and the lower surface of said base.

5. The device according to claim 4 wherein the elastomeric material is a polyurethane material. 

1. A side bearing for railroad cars comprising an upstanding symmetrical body member of frustoconical shape, the upper medial bearing surface being flat, a flanged base integrally formed on the lower end of said body member, said body member and base being formed solely of an elastomeric material having a hardness of at least 50 Shore D Scale, the perimeter of said upper surface extending downwardly and outwardly therefrom and merging with the sidewall of said body member, and a rod extending medially upwardly in said member from the lower surface of said base.
 2. The device according to claim 1 wherein the body member and base are bored axially, a rod having a length less than the length of the bore positioned in said bore, and the rod being frictionally seated in said bore.
 3. The device according to claim 2 wherein the hardness of said elastomeric material is at least 50 to 90 Shore D Scale.
 4. A preloadable side bearing for positioning between the frame of a railroad car and the truck bolster comprising an integrally formed, flanged base and an upstanding symmetrical body member of frustoconical shape, said base and body member being formed of an elastomeric material having a hardness of at least 50 to 90 Shore D Scale, the medial portion of the upper surface of said body member being flat with perimetrical portions angled downwardly, a cylindrical rod embedded axially in said body member and having a length substantially less than the height of said base and body member, and an axial opening between the lower end of said rod and the lower surface of said base.
 5. The device according to claim 4 wherein the elastomeric material is a polyurethane material. 